The ambulanceman gave Ali the job of keeping his mother alive. The 12-year-old did what he could. "Mama, mama, don't go to sleep," he sobbed, gently patting her face beneath her chin. Behind her black veil, her eyelids were slowly sinking. "I'm going to die," she sighed. "Don't say that, mama," Ali begged, and then slid to the ground in tears.

On the pavement around mother and son were the other members of the Sha'ita family, their faces spattered with each other's blood. All were in varying shades of shock and injury. A tourniquet was tied on Ali's mother's arm. A few metres away, his aunt lay motionless, the white T-shirt beneath her abaya stained red. Two sisters hugged each other and wept, oblivious to the medics tending their wounds. "Let them take me, let them take me," one screamed.

Their mother was placed on a stretcher, and lifted into the ambulance. "God is with you, mama," Ali said. She reached up with her good arm to caress his face.

The Sha'itas had thought they were on the road to safety when they set out yesterday, leaving behind a village which because of an accident of geography - it is five miles from the Israeli border - had seemed to make their home a killing ground. They had been ordered to evacuate by the Israelis.

But they were a little too slow and became separated from the other vehicles fleeing the Israeli air offensive in south Lebanon. Minutes before the Guardian's car arrived, trailing a Red Cross ambulance on its way to other civilian wounded in another town, an Israeli missile pierced the roof of the Sha'itas' white van. Three passengers sitting in the third row were killed instantly, including Ali's grandmother. Sixteen other passengers were wounded. In recent days, families like the Sha'itas are bearing the brunt of Israel's air campaign and its efforts to rid the area of civilians before ground operations. A day after Israel's deadline for people to leave their homes and flee north of the Litani river, roads which in ordinary times wind lazily through tobacco fields and banana groves have been turned into highways of death.

Plumes of smoke rise in the distance, and the road in front of us offers up signs of closer peril: car wrecks, still smoking after Israeli strikes, and abandoned vehicles with shattered rear windows. Some were direct hits by Israeli aircraft. Others were drivers who had lost control. Overhead is the menacing roar of Israeli warplanes and the buzz of drones tracking every movement.

With bridges on the main coastal roads severed by Israeli air strikes, and secondary mountain routes scarred by craters, the means of escape for Lebanese trying to follow Israel's orders are limited. "All the smaller roads leading to the coastal roads are destroyed," said a spokesman for the UN in the border town of Naqoura. "In some areas you have people pushing cars by hand through obstacles made by a rocket or a bomb." By yesterday afternoon, for many villagers, there was truly no way out.

Death came crashing into the Sha'ita family soon after 10am, in the form of an Israeli anti-tank missile, seemingly fired from an Israeli helicopter high overhead, in Kafra, about nine miles from their home. Those passengers who were not killed or injured by shards of burning metal were hurt when the van plunged into the side of a hill.